Known in the prior art is a cock or valve in which the plug is inserted into a tapered hole within a sleeve previously placed in the hole. The different connections between the fluid, air or liquid passages are made by turning the plug. All parts in this cock are made of metal with the contacting and the rubbing surfaces specially treated to avoid fluid leaks. However, any pollutant or foreign material in the fluid may stick to the metal surfaces, causing damage at least to the treated surfaces and thus creating leaks. Retreatment of the surfaces is possible but this frequently changes the diameters of the hole, sleeve, and/or plug, so that the parts do not fit tightly and replacement is required. One solution was to install a spring to provide firmer contact between the various surfaces, but this can greatly increase the operating force required. In another solution, the rubbing surface of the plug is made spherical in shape and an elastic valve seat used to bring the metal surface and spring surface into contact. This does produce tighter contact between contacting and rubbing surfaces, does not require special surface treatment, and reduces the required operating force. However, this ball cock has smaller contacting surfaces so that it is difficult to close each passage tightly to prevent fluid leaks. The ball cock is not usable for 3- and 4-way cocks with multiple passage ways. There is a need, therefore, for a cock with multiple passages which overcomes these deficiencies.
Accordingly, an object of my invention is an improved cock which eliminates the necessity for treatment of contacting and rubbing surfaces while maintaining tight seals to avoid fluid leaks.
Another object of this invention is a cock in which an elastomeric sleeve is inserted between the surface of the hole in the cock body and the operating plug mounted in the hole with a free turning movement to connect the several passages, and with spring pressure to assure a close fit between contacting and rubbing surfaces of the three elements, one pair of such surfaces being tapered.
Other objects, features, and advantages of the invention will become apparent from the following specification and appended claims when taken in connection with the accompanying drawings.